Geiger counter



Oct. 25, 1949.

| GOLDSTEIN GEIGER COUNTER Filed Feb. l, 1947 wash. mbl

IN VEN TOR. A0/.WAS 60.4 srE//V A TTOZPNE'Y' Patented Oct. 25, i1949GEIGER COUNTER f Ladislas Goldstein, New York, N. Y., assignor toInternational Standard Electric Corporation, New York, N. Y., acorporation of Delaware Application February 1, 1947, serial No. 725,827

6 Claims.

This invention relates to devices that detect, and usually give aquantitative indication of, the presence of radioactive substances,atomic particles and radiation, such as cosmic radiation, etc. Thesedevices include those entitled Geiger counters.

An object of the present invention is the provision of an improveddevice of the type hereinabove described.

Another obj ect is the provision of such a device that is characterizedby high sensitivity and thus enables dispensing with additionalamplifiers.

A feature of the invention is that it permits the construction of small,light weight portable devices of the type hereinabove referred to.

The above-mentioned and other features and objects of this inventionwill become more apparent and the invention itself though notnecessarily defined by said features and objects will be best understoodby reference to the following description of an embodiment of theinvention taken in connection with the accompanying drawings, whereinthe gure is a schematic side view, partly in cross section, of a deviceof the type described.

Referring now to the drawing, the apparatus includes an opaque containerl which blocks out external light from the apparatus contained therein.Within the container I, there is provided a Geiger-Mueller counter tube2 which may be provided with the usual wire anode 3 and cylindricalcathode 4 arranged within an envelope 5. Within the envelope 5, asuitable gas or gases 6 are provided, as is well-known to those versedin the art.

In the usual Geiger counter arrangement, a potential is applied betweenthe anode and cathode and when the tube is excited by penetrating rays,such as for example, by gamma rays, to iom'Ze the gas within theenvelope 5, current flows in the circuit connecting the anode andcathode and this current is measured or the number of pulses of suchcurrent is counted to detect the presence yof the rays and the intensitythereof. 'I'hese pulses have to be considerably amplified before theycan operate a counter arrangement. Thus Geiger counters tend to berelatively unportable or bulky because of the amplifiers required.

The present invention operates on a different principle. When the gas 6in the Geiger-Mueller counter tube is ionized and potentials are appliedbetween the an-odes and cathodes, in addition to pulses of current beingproduced in the associated circuit, photons are emitted. In accordancewith the present invention, the pulses in the circuit associated withthe anode and cath- 0de are not measured but the photon emission is. Forthis purpose, the Geiger-Mueller tube 2 has one portion of its envelope,such as for example, the end l, provided with a wall which permits lightradiation to pass through with little absorption thereof. Thephoto-electric multiplier 8 is arranged adjacent to the Geiger- Muellertube 2 to receive the light therefrom and to be excited by said light toproduce a current response thereto. While the photoelectric multiplierrequires'relatively high potentials, it does not use much currentparticularly at the lower stages thereof. Therefore, if it is desiredthat the apparatus be portable, a very small power supply unit 9 may beused capable of giving the desired potential without having particularlylarge capacity. Power supply 9 not only is coupled, as indicated by thelines II), to the photoelectric multiplier to provide current therefor,but also supplies potential to the anode and cathode of theGeiger-Mueller counter tube.

A suitable indicator I I may be provided which has at least theindicating face I2 thereof visible and for this purpose the indicator llmay be mounted on the outside of the container I. The indicator I I iscoupled to the output in the photoelectric multiplier and may be of anyone of several types. For example, the indicator I I may be a, typicalcounter used in Geiger counter arrangements which serves to totalize thenumber of pulses produced. Another form which indicator II may take, isthat of a current reading instrument, and may be particularly a currentreading instrument which will integrate the current being passed or givean average thereof. The indicator I I may also be a combination of acounter and such a current reading instrument.

As will be appreciated, various photoelectric multipliers provide theirmaximum response to light at different frequencies. Likewise, it will beappreciated that by the use of different gases 6 within theGeiger-Mueller tube 2, light radiations having their maximum intensityat different frequencies, may be obtained.

It is therefore preferred to select the proper gas 6 with relationshipto the maximum response of the photoelectric multiplier 8 so thatmaximum sensitivity may be obtained. Of course, it is to be understoodthat the term light radiation is used broadly to cover the entire lightrange from infra-red to ultra-violet and the term is not intended to beconstrued narrowly. Furthermore, more broadly, it is to be construed asapplying to principles of my invention in connection with;

specific apparatus, it is to be clearly understood that this descriptionis made only by Way of example and not as a limitationaon the scope ofmy invention.

I claim:

1. A Geigercounter arrangement. comprising.

a Geiger-Mueller counter tube adapted to emit light radiation uponexcitation, a source of p0- tential, means for applying said potentialto said tube,ay photoelectric device arranged to, be ex+ citedfby llightradiationl iromsaid tube, andmeans associated'with said device andresponsiveto the current .ilow therein for indicating the lightradiation from said tube;

2. An arrangement according-torclaimd Wherein said device is arrangedadjacent saidtube.-l

3. An arrangement according toclaim lwhere-v '4 in said device isarranged adjacent said tube and said tube includes an envelope having aWall adjacent said tube having low absorption characteristics for saidlight radiation.

4. An arrangement according to claim 1 further including means forpreventing light radiation from any external source from entering saidtube and said device.

5. Anvarrangement according to claim 1 further including a light opaquecontainer at least partially surrounding said tube and said device. 6..An arrangement according to claim 1 Wherein said photoelectric deviceis a photoelectric multiplier, and means for applying potential from.said.; source: to said multiplier.

LADISLAS GOLDSTEIN.

REFERENCES CITED The following references are of record'in the iile ofthis patent:

UNITED STATES PATENTS Number Name Datey 651,013 Kitsee June 5, 19001,850,467 Nakken Mar. 22, 1932 2,200,722 Pierce et al. May 14, 19402,409,498 Keston Oct. 15, 1946l

